CoAxe Pickups: Interview with Vox R&D

Wednesday, May 18th, 2011 at
8:41 pm

As you can hear in my recent video review of the Vox SSC33, the Vox CoAxe pickups sound amazing. They’re dynamic, noiseless in all modes, and most importantly offer up a wide range of incredible sounds.

With the two blades sandwiching the pole pieces, you can see right away that these aren’t your typical humbucker, single-coil or P90…

Curious for more details on these mysterious creations, I got in touch with the man behind the magic- the inventor of the CoAxe pickup: Eric Kirkland, Chief Designer at Vox Guitar Development (G-Rok), in Novato, California. Read on…

Why the name CoAxe?

Eric: The name “CoAxe”, of course, refers to the orientation of the coils. Stacked humbuckers (the so-called “stacked single coil” pickups) are also coaxial, but our pickups are co-planar as well. Maybe “Concentric” would have been a more descriptive name, but it just didn’t sound cool enough.

Tell us about those blades, poles and coils!

Eric: The arrangement of the coils is significant, as is the position of the blades between the coils. The inner sensing coil, with its load of six poles, works like any single coil. Since the load of the outer noise canceling coil consists of both the six poles and the two blades, less wire is required to produce a noise signal equivalent to the noise in the inner coil. Less wire means less impedance, so the Clean and Crunch modes can be both noise-free and sparkly. (Exposed to typical ambient EMI, our pickups have less noise than a covered Gibson PAF type humbucker – and more output.)

What type of magnets are used?

Eric: Ceramic – very similar to those used in the Three-90. The higher coercivity of ceramic (compared to Alnico) makes it possible to develop enough power across the available space between the poles and the blades.

What are those “Crunch”, “Lead” and “Clean” modes, really?

Eric: Beyond the bandwidth and signal/noise advantages from the coil arrangement, we get the different voices by selecting either the tap or full winding of both the inner and outer coils. So two poles of switching are required for each pickup, or a 4PDT master as on the Series 33. Further, the Series 55 makes a third mode available by adding passive filtering to shape the Crunch sound into the more mid/less treble Lead sound. This requires another two poles of switching for each pickup, or a pair of 4PDTs.

Do you mean “4P3T” there for three-way switch in the 55?

Eric: Using standard switch nomenclature, they are 4PDT as there are only two “throws” available for each pole. In the middle position, half the poles go one way and half the other. To be more specific I should have called them “4PDT On-On-On” to distinguish them from the somewhat more common two position 4PDT, as used on the Series 33.

How does the CoAxe compare with other humbucking pickups?

Eric: It has always annoyed me to see manufacturers focus on DC resistance. IF every other component were held equal, DC resistance can give you some idea of the output level and tone of a particular kind of pickup. But since there are so many other variables, it doesn’t really tell you much except the approximate length of wire used – assuming you know the gauge. A better indicator is inductance. On the CoAxe, the inductance of the Clean mode is around 3.1 H, which is about what you would see in the single coil pickups from a certain large manufacturer whose name begins with F. The inductance of the Crunch mode is around 5.3 H, and the Lead mode measures around 6.3H.

Are the bridge and neck pickups identical, or are they wound differently?

Eric: They are just the same, and the appropriate levels are dialed in by height adjustment. We tend to run the neck pickup relatively far away from the strings to balance it with the bridge pickup and avoid interfering with the string vibration.

How do the CoAxe pickups differ from the Three-90 in the Virage?

Eric: The Three-90 has three conventional (side-by-side) coils that are combined in various ways to create the different sounds. Two adjacent coils are combined in series for the ‘lead’ voice, the outside coils are combined in series for the ‘crunch’ voice, and two adjacent coils are combined in parallel for the ‘clean’ voice.

The Three-90 gives a great range of tone change across the modes. For the CoAxe, however, we wanted to increase the output level of the ‘clean’ mode for a more aggressive single coil sound. Also, we wanted to add some emphasis to the attack on all modes, so we went with a separate polepiece for each string in the sensing coil.

The CoAxe produces a relatively strong magnetic field, so if the pickups (especially the neck pickup) are too close to the strings, the strings (especially the bass strings) can’t vibrate properly. So height adjustment will be more like a traditional single coil than a traditional humbucker.

A good starting point would be to set the neck pickup between 1/8″ and 3/32″ from the E strings, with the strings fretted at the 22nd fret. Then adjust the bridge pickup to for the volume balance you prefer.

thanks very much : ) nice to have an answer from the genious himself . on a slightly different point i was wondering if you or any one had any info/specs of an acoustic v2000dr i also have , but cant find out anything other than they were build in japan in 2010, dont know how many, type of electronics/woods etc any help would be great

Great interview! It inspired me to get a custom Vox Butterfly made here in Japan at Fujigen. It’s a great guitar playing, sounding and looking guitar EXECPT that the low E-string sounds farty with the neck pickup. I’ve tried adjusting everything to fix it except flatwounds which aren’t really a solution for me. Is it possible I got a dud?

I had assumed they were made by Fujigen, but learned recently they were actually made at another Japanese factory that is supposed to be even better. Interestingly, Diamond pedals are made there, too.
Try a search for Vox Butterfly using Yahoo! Japan to see some offerings.

Eric…can you direct me to more info on the xlm pickups on the sdc22? Any info like in the pics above?….I am curious as to how the 2 tones are made with the pickup…i understand the leadhumbucker mode is the mini humbucker..but when in the other mode its very single coil like so are coils tapped?..split? or it is in parralel?I ask because i wonder how they are so quiet in both modes(i understand the full humbucker mode but the thinner mode is so quiet?) thanx

I own an original Virage. I love it, but have been really curious about the CoAxe pickups; the way they are described here make them sound like they would be an improvement over the Three-90, but I would obviously like to hear them side-by-side before committing to putting them in my Virage. Is there a demo video out there somewhere that does this? Also, how would I purchase the CoAxe pickups if I chose to do so? I can’t find anything about buying them on their own on the Vox site.

I bought a Virage1 and felt the three-90s sound round, and are VERY responsive to pick attack. Then I read this interview and decided the CoAxe would be better suited to my style. They do have more attack and clarity like it says in the interview, but I find the CoAxe to be more versatile. The output is more consistent across each mode, too. Basically, if you like humbuckers I think the Three-90s are the way to go, but if you prefer single-coil sounds the CoAxe are a better bet.

Incidentally, I decided to sell the Virage 1. It’s a deep cherry single-cutaway in good condition, but it will probably have to be shipped from Japan!

One other question: are there any tremolo systems that can be mounted on the Virage? Or does Vox have plans to develop one? I would assume it would be a Bigsby-style unit. The lack of that option is really the only thing that stops the guitar from being perfect for me. Given the success with which Vox updated a class 335-ish design here, I’d be very interested to see what they would do with a tremolo.

Thanks for enduring my Virage barrage. This is the only page I’ve found that addresses my specific question.

Here’s a link to the latest revision of the harness drawings for all models in the series. Note that the 55, 77, and Virage II have basically the same electronics, but with longer cables between the mode switches and pickup selector on the semi-hollow models.

I just picked up a Trans Amber HDC-77, and I’d like to start out by saying that I LOVE this guitar. The ability to get true single coil, P-90, and humbucker sounds without switching guitars or amp settings is heaven. That being said, I have one problem with mine: I think that the bridge pickup is too high, because it just sounds a little too “hot” for me (I.e. too early of a breakup on the 3 bass strings). I’ve tried to lower it, but I can’t seem to get the screw to turn, in either direction. Should I take it to my trusty luthier, or is my fate sealed, as they say. Again, fantastic guitar, just one minor problem. I’m eagerly awaiting your response.

Congratulations on the new 77- beautiful guitar!
Those pickups are certainly height adjustable. You turn the mounting screws clockwise to lower them, for less output. You may try turning them counter-clockwise at first, just to get the screws moving.
Make sure you are using the right size of screwdriver, to fits the screws well, so you don’t damage them as you apply the force necessary to get them to “unstick”.
If you still can’t get them adjusted, your trusted luthier friend should have the right screwdriver- and I can’t imagine him charging you for the help, as it should take about 2 seconds.
Good luck!
-John

Hi , i have a Koa HDC 77 , amazing guitar ! can i get a replacement bridge anywhere ?, i would just like to have a spare . again amazing guitar , I find having the pick ups fairly low into the body makes the guitar breath more , more tone and sustain is defiantly achieved by this , and by reading this article and learning about the hot magnets now i know why awesome guitar , well done

Thanks for the kind comments on the Koa 77! Unfortunately, we just don’t have any stock of bridges (or much of anything else) to sell. Not to worry, though. If you have any trouble with the bridge, let us know and we’ll find a way to get it taken care of. One thing to keep in mind – though the aluminum bridge base is a unique part, the saddles are made to Gibson TOM (“Nashville”) specs so suitable replacement are available from a number of sources.

Im in the uk , i have emailed the old uk supplier to see if they have any(long shot) I would just love to have spare, I’m pretty sure thats were a lot of the sound comes from , even acoustically its rings beautifully , its has a glistening top end !! I will probably buy another one at some point but you just dont see them for sale even second hand over here anymore ,( i think Prince has had a lot to do with that)

I just checked with our planning/purchasing guys – it seems the run was limited to 80 pieces. As for output, its difficult to give a meaningful figure. The max. DC resistance (full sensing coil + full NC coil) is around 8K, but the output and tone are quite different from, for example, a PAF-type pickup with an 8K DCR. Output voltage would probably be a more useful figure, but there are so many variables (distance from string, string diameter, picking force) that we’ve never tried to measure it.

A few years ago, we designed a short scale bass with a CoAxe pickup on a Virage-type body. I think the combination worked well – the CoAxe seemed to give the short scale some needed clarity. We sent the only prototype to an artist for his feedback, though we don’t have any current plans to launch a production model.

I admit to abhorring the 19mm Fender Standard spacing. I prefer the narrow spacing once found on the majority of inexpensive Asian imports, like the Teisco / Kawai, as well as other non-Fender basses (Hofner, Rickenbacker, Guild, Carvin, Alembic). Many who have become accustomed to narrow spacing on their 5 and 6 string basses are realizing that the FSB w-i-d-e spacing is far less ergonomic and an impediment.

Im just hoping i never need one for the three i have two 55s and a 77, im guessing from the new vox web site they have all been discontiued, a shame great guitars, but the spaqres issue, pots etc might now be an issue

The P-90 crunch sound is achieved by adding some passive filtering to the lead sound. It’s the exact same pickup with the same wiring for the tap and full-windings. So yes, it seems like you could modify your 33 by replacing the switch, and adding the necessary resistors/caps in the crunch position to match the SSC-55. The 55 also provides independent selection for each pickups – this would require drilling new holes in the body, etc.
-John

The SDC-22 pickup is much more “normal” than the CoAxe, and has two adjacent coils like most humbuckers. The thing that makes it different is the loading – the pole screws are larger diameter than usual, increasing the inductance. The two sounds are simply series and parallel, but because of the higher loading the parallel voice is less of a level drop compared to a standard humbucker.

this is kind of what i had thought….they sound very good…in both positions..i wonder if having separate switches for each pickup would be valuable in the middle position where each pickup can be either series or parr…i mean it may not be worth the effort…

I am 4 days away from receiving my [used] SSC-55 and I am really excited about it. I owned one of the first year Virages and I loved that guitar – sold it in a moment of stupidity. There are few guitars that I “remember” how well they played. Out of about twenty or so guitars I have owned, that Virage and a Strat built by John Cruz are the only two…

Sad to see the SSC/SDC series having ended production…but looking forward to having mine.

i have just bought a ssc22 and the guitar is sweet…no neck dive like the sdc33/55 guitars…i tried a 33 recently and was not overly impressed with the pickup sounds…the mod switch(only 1 on the 33) varied very little and was very subtle on the guitar to make any impact to me. I have yet to try the 55 series..but i came across a used sdc22 and was blown away by the pickup tones..the mod switch made a ton of difference and the pickups are very knarley and scream as humbucking but get very straty and tele like when the mod switch is engaged….I am considering adding another switch so there is one for each pickup..does anyone have the schematic for the 22 series?…i am guessing this can be done easily…thanx..

You’re in luck – this mod can be done easily. Just install a pair of the kind of 2-position DPDT switches people often use on guitars, and follow the wiring on the stock 4PDT. (Wire the left DPDT like the left half of the 4PDT, and so on.) There’s a link to the hookup diagrams higher in this thread.

Thank you….so i can keep the switch that is there now..it is a 2 way mini toggle….and add another same switch? I am sorry i am new to wiring….i take it both pickups are wired to the 1 switch so are you saying i would need 2 NEW switches(look same(on/on) but different lugs?? and wire each pickup to each switch? Thank you for the info

Eric…i would like to convert my 33 to a 55 swiching wise..any link to a wiring diagran to do this?..hsuru4u@yahoo.com is my email..
i take it i would have to do these things>
1) remove the 2 position toggle
2) drill second hole for another toggle
3)get 2 3way toggles for this mod like the one i remove but with 3 positions vs the 2 on the 33
4) figure how to wire it and add any other resisters or caps to the switch to get the p90 effect?

Have these guitars been discontinued? I have been looking around and cannot find any sign of them on the vox website (or signs of any vox guitars for that matter). I have a SDC33 and was looking to get a SSC55.